Intraocular surgery typically requires dilation of the pupil to access posterior tissues from a visual and surgical standpoint. Cataract surgery and retinal surgeries in particular require a well-dilated pupil that allows for visual targeting of tissues posterior to the iris. Many patients do not respond to pupil dilation drops and require the use of various devices to expand the pupil mechanically.
Various ophthalmic procedures require the dilation of the pupil. It is desirable to extend the pupil during the procedure to provide the surgeon with a wide view of the lens. Known techniques for extending and pulling back the iris can cause damage to iris tissue. Patients who have a small pupil pose a major problem and challenge during ophthalmic surgery. When such a patient has cataract or vitreo-retinal surgery and their pupil cannot be easily dilated by mydriatic eye drops, the surgery becomes difficult unless the pupil can be mechanically dilated. Current styles of iris supporting rings tend to snag the incision into the eye as the rings are being removed from the eye after use. This not only make removal more difficult, but it also can lead to the ring scrapping against the endothelial cells lining the inside of the cornea as the surgeon attempts to free the snagged ring. Pharmacological approaches for managing a small pupil during cataract surgery have limitations. A significant problem for the surgeon is decreased visualization, iris trauma due to incarceration into the wound, iris chafing, pupillary margin damage by needles and others. For example, cataractous lenses are typically replaced in a procedure commonly referred to as phacoemulsification. For this procedure, the lens is broken up with an instrument, typically with an ultrasonically driven tool. To perform this procedure safely a surgeon needs to visualize the entire cataracteous lens. There is need for a better technique and device for safely dilating the iris.
During ophthalmic surgery, it is sometimes desirable to enlarge an opening in eyeball tissue, such as, for example, holding the iris open for access through the pupil. It has been proposed that, at least in some cases, expansion be achieved mechanically by one or more devices that engage against opposing edge portions of the eyeball tissue, such as inner edge portions of the iris. Many current devices suffer from significant issues with ease of implantation and with ease of removal once the surgery is over. In addition, the dilation that is produced by most devices results in significant stress on the iris and produces inflammation and atrophy of tissue after surgery. What is needed is a device that is conducive to easy insertion and removal as well as being optimized for atraumatic pupil expansion.